Soaping Or Soaping Off

SOAPING (OR SOAPING OFF):- 

WITH RESPECT TO DYEING, THE PROCESS WASHING DYED FABRICS WITH VERY HOT (OFTEN BOILING) WATER WITH SURFACTANTS AND SOAP TO REMOVE DYE THAT IS NOT FIXED TO THE FIBRE; SOAPING OFF IS IMPORTANT PARTICULARLY WITH SOME REACTIVE DYES, SINCE A GOOD DEAL OF HYDROLYZED DYE IS LOOSELY BONDED TO THE FABRIC, AND MUST BE REMOVED TO AVOID STAINING OF OTHER GARMENTS OR FABRIC IN LAUNDERING; SOAPING IS ALSO IMPORTANT IN VAT DYEING, WHERE THERE ARE ACTUAL CHANGES, INCLUDING HUE,IN THE DYE IN THE FIBRE; THOUGH SURFACTANTS ARE OFTEN USED, THEY MAY ACTUALLY CONTRIBUTE ALMOST NOTHING TO THE EFFECTIVENESS OF THE PROCESS.